The purpose of this renewal application is to continue our efforts to impact the behaviors that place injection drug users (IDUs) at risk for HIV infection. Beginning in 1987, we conducted community-based interventions with IDUs in Denver to prevent HIV infection using the Indigenous Leader Outreach Model. The model focused on promoting the alteration or elimination of specific behaviors that place IDUs at risk for infection. While significant reductions in HIV risk-related behaviors occurred, many IDUs remained at risk. In an effort to extend our intervention message beyond safer injection practices, in 1995 we initiated an intervention designed to encourage IDUs to enter treatment for their drug addiction and quit their use of drugs. The intervention, based on the principals of motivational interviewing (MI), focused on moving IDUs along the 'stages of change' continuum. Although more than 40% of those we have intervened with to date entered treatment, we feel we can improve our efforts to achieve abstinence by increasing the time allotted to motivate more resistant IDUs and by addressing the multiple needs they have that impede their desire to change. Using a cross-over experimental design, 760 IDUs will be randomly assigned to one of four conditions: l. an expanded MI intervention that tailors the number of interventions to the individual's stage of change; 2. a case management model with an emphasis on securing services specific to the needs of the individual: 3. a combined MI and case-management approach; and, for comparison purposes, 4. the community-based intervention model we have used since 1987. Since psychological factors may account for the capacity to take advantage of interventions offered, and thus serve in a mediating role, we propose to include measures of psychological co-morbidity as potentially important outcome predictors.